title: Serum-free culture of rat proximal tubule cells with enhanced function on chitosan.
abstract: The proximal tubule performs a variety of important renal functions and is the major site for nutrient reabsorption. The purpose of this study is to culture rat renal proximal tubule cells (PTCs) on chitosan without serum to maintain a transcellular pathway to transport water and ions effectively without loss of highly differentiated cell function. The effect of chitosan, which is structurally similar to glycosaminoglycans, in the absence of serum on the primary cultured PTCs was compared that of collagen with or without serum. Two days after seeding, more tubule fragments and higher PTC viability were observed on chitosan than on collagen with or without serum. Proliferation marker Ki-67 immunostaining and phosphorylated extracellular-regulated kinase (ERK) expression results displayed similar proliferation capability of PTCs established on chitosan without serum and collagen with 2% fetal bovine serum after 4 days of incubation. When grown to confluence, PTCs formed a monolayer with well-organized tight junctions and formation of domes on chitosan without serum. Moreover, evaluation of the transepithelial electrical resistance showed that both chitosan and serum were involved in the modification of water and ion transport in confluent cells. By showing the direct suppression of PTC growth and dome formation treated with heparinase, we demonstrated that the interaction between cell surface heparin sulfate proteoglycan and chitosan played an important role in PTC proliferation and differentiation. A successful primary culture of PTCs has now been produced on chitosan in serum-free culture condition, which offers potential applications for chitosan in renal tissue engineering.
authors.affiliation: Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Shao-Hsuan
authors.initials: SH
authors.lastname: Chang
authors.forename: I-Ni
authors.initials: IN
authors.lastname: Chiang
authors.forename: Yi-Hsin
authors.initials: YH
authors.lastname: Chen
authors.forename: Tai-Horng
authors.initials: TH
authors.lastname: Young
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D017097:Electric Impedance; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019763:Heparin Lyase / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D015820:Cadherins; D016895:Culture Media, Serum-Free; D062826:Zonula Occludens-1 Protein; D003094:Collagen; D048271:Chitosan; D000469:Alkaline Phosphatase; D019763:Heparin Lyase; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Chitosan; Collagen; Dome formation; Proximal tubule cells (PTCs); Serum